BUG: stats: distribution methods emit unnecessary warnings from Boost

Describe your issue

Several statistical distribution methods emit warnings stemming from Boost. This issue tracks the status of all of them.

• beta.ppf as reported here; should be fixed by boostorg/math#827
• ncf as reported in gh-17101, should be fixed by boostorg/math#846
• nct - I’m not sure that this has been reported separately yet. Is it caused by the same sort of thing?
• ncx2 - Ditto.

gh-17272 will silence the failures in SciPy’s tests temporarily, but as many of these marks as possible should be removed when gh-17207 merges.

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Original Post

Describe your issue.

macOS CI is failing due to an overflow. I am still trying to reproduce locally.

NumPy was updated to 1.21.3, could be this or another dependency.

https://github.com/scipy/scipy/runs/3960228039

Reproducing Code Example

# from scipy/stats/tests/test_distributions.py:2878: in test_issue_12796
import numpy as np
from scipy import stats
q = 0.999995
a = np.array([ 2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20])
b = np.array([99999, 99998, 99997, 99996, 99995, 99994, 99993, 99992, 99991, 99990, 99989, 99988, 99987, 99986, 99985, 99984, 99983, 99982, 99981])
stats.beta.ppf(q, a, b)

Error message

FAILED scipy/stats/tests/test_distributions.py::TestBeta::test_issue_12635 - ...
927
FAILED scipy/stats/tests/test_distributions.py::TestBeta::test_issue_12794 - ...
928
FAILED scipy/stats/tests/test_distributions.py::TestBeta::test_issue_12796 - ...
...
scipy/stats/_continuous_distns.py:626: in _ppf
916
    return _boost._beta_ppf(q, a, b)
917
E   RuntimeWarning: overflow encountered in _beta_ppf

SciPy/NumPy/Python version information

master on macOS/CI

[mborland]

nct should be fixed by https://github.com/boostorg/math/pull/892. I’ll look at ncx2 this week.

[mdhaber]

I believe that PR to Boost will resolve this issue, but we haven’t updated the commit of the Boost submodule in SciPy main yet, so we still see these failures in SciPy main right now. I’m about to submit a PR that silences those warnings, so I’m using this issue as a reminder to un-silence such warnings after the Boost submodule commit gets changed. We’ll close this issue when they’re all passing. Thanks for your help @mborland!